This is a follow-up of the work done in fa42c2ec, that did not include
all the fixes previously agreed on.  The contents removed here can be
confusing to the reader as they refer to rather old server versions.

Author: Stephen Frost, Tom Lane, Heikki Linnakangas, Yaroslav Schekin
Discussion: https://postgr.es/m/CAB8KJ=jYHgnxLLZSNJz7gBTck4TxomngCmGkw3nEMSNF0yL6wA@mail.gmail.com
Discussion: https://postgr.es/m/1599765595731-0.post@n3.nabble.com